The present invention generally relates to a hand held implement which is capable of computing at least one and typically would perform numerous calculations, generally using a single set of input variables (which are related by their mathematical formulas and/or their interrelated technological relationships or values). For example, a physician may use such an implement to calculate the various physiological relationships for a patient, such as their Body Mass Index, Body Surface Area, Creatinine Clearance and Hemoglobin A1C to Mean Plasma Glucose Estimation and other associated measures. In the past, upon examining a patient and obtaining his or her vitals, the medical service provider would then refer to separate specific formulas and tables to compute the desired information for the patient.
Similarly, professionals such as mortgage brokers or car salesmen, engineers, mechanics or bartenders commonly encounter repetitive needs to conduct calculations based on mathematical formulas. In the case of an engineer, he or she may require a calculation for stress, bending, forces, torque and many other measures. Mortgage brokers and salesmen may need to calculate interest rates, down payments required, monthly payments and other calculations derived from the same basic known formulas.
While hand held calculators may perform some of these functions, their very size and nature, make them not as desirable as an implement the size of a writing pen. Moreover, previously designed calculators typically perform singular functions and do not incorporate preprogrammed mathematical formulas for the calculation of specific measures or values required in particular fields of use. Moreover, commonly known calculators can not be secondarily used as a writing implement, stylus or other pointed tip type of instrument.
The need for a calculating product incorporated in a hand held implement has been attempted in the past. U.S. Pat. No. 5,028,764 to Kuhlengel discloses a pen with rotatable cylindrical elements that is used to perform a simple calculation in the multiplication of two numbers. In this patent, the invention provides its user no capability to perform a specific calculation based upon a preprogrammed known scientific formula, as the pen will not permit a calculation other than basic multiplication and relies upon the user to supply a formula. U.S. Pat. No. 4,141,073 to Tan describes a pen which may be used to perform various calculations. In that pen, signals generated by the pen tip through designated strokes of numerals and calculating symbols upon writing on any surface of any writing medium are input directly to the calculator to perform calculating and displaying functions. The Tan invention therefore is doubly complicated as it relies upon the user to know or refer to a specific formula and thereafter demands the user essentially tap out a series of carefully orchestrated movements in order to perform even the simplest calculation. Therefore, neither patent involves a device which may be employed to quickly determine the numerical outcome of a specific formula or equation, such as the Body Surface Area of a person, based jointly on multiple variables, in this case the two factors being their height and weight.
U.S. Pat. No. 6,104,603 to Wang discloses a writing pen with an integral electronic calculator including printed circuit board, keyboard and power supply. While this invention is perhaps more versatile than those of Kuhlengel and Tan, it too is nothing more than the insertion of a hand held calculator into a pen. The user must still refer to outside formulas and take care to properly input any specific variables if they wish to perform a calculation based on a specific known formula. Moreover, that device has little or no capability to handle non-linear and other unusual relationships between variables in a known scientific formula, such as those physiological factors for which different values must be used for each sex.
Perhaps the biggest drawback of these types of calculating implements is the user must input the required variables each time they wish to perform a calculation. For example, a doctor using these implements would have to perform two separate calculations and input the same numerical values twice if, for example, they wished to compute a patient's body mass index and their body surface area, despite the fact that these related calculations are both based on the patients height and weight. The requirement for repetitive inputting of the same numerical values only serves to increase the prospect of human error, which in the medical profession may give rise to serious consequences.
U.S. Pat. No. 6,890,117 to Hazzard describes a calculating pen for calculating the body mass of an individual. This invention, however, is manually operated and fails to include an electronic calculator. It is therefore limited in the scope and range of calculations which may be performed with any given implement.
What is needed is a hand held implement which is designed for use in a specific field whereby its incorporated electronic calculator is preprogrammed with the particular variables and mathematical formulas required on a repetitive basis in the field. To have a simple hand held device on which the user may input a set of numerical values for particular variables to compute a specific formula result for a known measure is highly desirable. Furthermore, a device which permits the user to input variables once and thereafter use those same variables for successive computations while using different formulas would render a significant benefit for time savings and error avoidance. This invention would permit the user to be free of voluminous and bulky manuals, reference books and other tools previously required and from which the scientific formulas may be gathered.
What would be most desirable is a hand held implement which incorporates an integral calculator and also avails user friendly interface controls such that the user may quickly and easily input the particular numerical values of interest and select the appropriate mode command to perform the desired computation.